by
Heidi Korhonen(Niels Bohr Institute, University of Copenhagen)
→
Europe/Stockholm
FA31
FA31
Description
Most young late-type stars are rapid rotators, because they have the primordial rotation rates induced by the interstellar molecular cloud from which they were formed. Also their older counterparts in close binary systems can show very high rotation rates. Rapid rotation enhances the dynamo
operation, and thus also introduces significantly stronger magnetic activity than is seen in slower rotators. This activity manifests itself, for example, as large starspots, strong flares and possibly numerous coronal mass ejections.
This is the environment in which planets are formed, and the activity could have a significant impact on the formation, evolution and habitability of the planetary systems. In addition, stellar activity can have effects on stellar
spectral lines that mimic radial velocity changes from an orbiting planet, making it at times difficult to distinguish between planets and activity signatures, and especially hampering the detection of small Earth-sized planets
using radial velocity method. In this talk I will discuss stellar magnetic activity, how we study it, what we know about it, and how it can affect exoplanets and their detection.